<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            border: 1px solid black;
            margin: 10px;
            padding: 20px;
        }
    </style>
</head>

<body>
    <div id="app">
        <div class="text">这是一个普通的div</div>
        <div class="box">这是一个普通的box</div>
    </div>



</body>
<script src="../js/demo.js">

</script>

</html>